1. Field of the Invention
The present invention relates generally to a medical tool comprising an electromechanical driver which transmits information to and receives information from, and thereby controls, a surgical instrument attachment, and more specifically to the mechanisms employed to provide such remote direction and information relaying between said electromechanical driver and said surgical instrument attachment.
2. Description of the Prior Art
It shall be understood at the outset, that the present invention has many applications within the field of surgery. This disclosure shall not, therefore, be read as limiting of the scope of the invention by the specific medical or surgical applications which may be described herein, as they are only used as elucidating examples of such applications in which the present invention may be employed to enhance the outcomes and/or surgical efficiency. In particular, the present disclosure is directed to embodiments used in colon surgery, and specifically to anastomosing, resecting, and stapling instruments, however, the same invention may be applied to other surgical applications in the fields of gynecological surgery, cardiovascular surgery, and general surgery.
Upon identification of cancerous or other anomalous tissue in the gastrointestinal tract, surgical intervention is often prescribed. The field of cancer surgery, and more specifically, the surgical procedure by which a section of the gastrointestinal tract which includes cancerous or anomalous tissue is resected, includes a number of uniquely designed instruments. In combination with a description of the present instrumentation and their functions, a description of the state of the art in this surgical procedure shall also be provided.
The first question which must be answered when determining how to treat gastrointestinal cancer relates to the specific location of the cancerous tissue. This is very important insofar as the instruments which are provided in the present art have limitations relating to how far they may be inserted into the gastrointestinal tract. If the cancerous tissue is too far up the colon, for example, then the standard instrumentation provided is unusable, thus requiring special accommodations. These accommodations generally increase the risk of contamination of the surrounding tissues with bowel contents, increase the length of the surgery and the corresponding need for anesthesia, and eliminate the benefits of precise anastomosing and stapling which comes from utilizing a mechanized device.
More specifically, in the event that the cancerous tissue is located at a position in the colon which is accessible by the present instrumentation, the patient""s abdomen is initially opened to expose the bowel. The surgeon then utilizes a linear cutter and stapling device which cuts the tube of the colon on either side of the cancerous tissue, thereby creating two stapled ends of the bowel (a distal end which is directed toward the anus, and the proximal end which is closest to the small intestine). This is done in order to temporarily minimize contamination.
The surgeon then partially opens the proximal end and inserts the removable anvil portion of an anastomosing and stapling instrument into the exposed proximal end. This step, as well as those of the remainder of the surgical procedure, are related to the functioning of this surgical instrument. More particularly, and with respect to FIG. 1, the surgeon begins by taking the instrument 30 and manually turning the dial 32 at the base of the handle 34 which causes the anvil head 36 at the opposite end to advance forward. The surgeon continues to turn the dial 32 until the anvil head 36 advances to its most extreme extended position. This manual turning requires nearly thirty full rotations. Once fully extended, the anvil head of the instrument is decoupled therefrom and is inserted into the partial opening of the proximal end such that the coupling post extends outwardly therethrough. This partial opening of the proximal end is then sutured closed. The extending shaft 38 of the anastomosing and stapling instrument 30 is then inserted and advanced into the lower colon, transanally, until the coupling stem 40 thereof extends through the stapled distal end. The surgeon then joins the coupling ends of the anvil and shaft together and begins to manually rotate the dial in the handle again, this time bringing the anvil head closer to the end 42 of the shaft.
Once the anvil head and shaft are brought close together, after the surgeon has manually rotated the dial another thirty times, a grip-style trigger 44 in the handle is manually actuated. This actuation causes a circular blade 46 to advance axially out from the tip of the shaft, and into contact with the opposing face 48 of the anvil 36. The blade cuts through the stapled-closed ends of the proximal and distal ends of the colon, thereby also cutting a new pair of ends of the proximal and distal portions of the colon. The tissue which has been severed is held in an interior volume at the end of the shaft.
In lock step with the cutting, the freshly opened ends are joined together by a series of staples 50 which are advanced through holes in the perimeter of the tip of the shaft (being pressed against and closed by the opposing face of the anvil). The coupled shaft and anvil are then withdrawn from the patient.
As with many such devices of the prior art, all of these devices are considered fully disposable, and are, in fact, thrown away after a single use. They are complicated devices, having multiple moving parts, requiring substantial structural integrity and, therefore, expense in manufacturing. The fact that they are used only once, and that no part can be used again, render the use of such devices expensive and wasteful of resources.
In addition to this failure, as can be readily observed from the preceding descriptions, the prior art devices suffer from numerous other limitations which would be desirable to overcome. These include the rigid and limited length shaft of the anastomosing and stapling instrument (which limits the portion of the gastrointestinal tract which may be treated by such a device), as well as the requirement that the surgeon manually actuate a number of different functions (including those associated with the dial and trigger of the anastomosing and stapling instrument and the multiple triggers of the cutting and stapling instrument).
Therefore, it has been a principal object of recent inventions to provide an instrument for cutting, anastomosing, and stapling, for use in gastrointestinal surgery, which reduces the waste of resources by permitting the reuse of portions thereof, can extend farther into the colon, and which are more simple to manipulate.
A substantial advance in the field of colon surgery has been disclosed in U.S. patent application Ser. No. 09/324,452, entitled xe2x80x9cAn Electromechanical Driver Device for use with Anastomosing, Stapling, and Resecting Instrumentsxe2x80x9d which was invented by the same inventor as the present application, was assigned to the same assignee as the present invention, and the specification of which is hereby incorporated fully by reference.
In particular, this prior invention, made by the present inventor comprises an electromechanical driver assembly, mounted in a handle-shaped base unit, which couples to and motivates remote surgical attachments through a flexible shaft which may also be remotely manipulated by means of a series of steering wires which are controlled within the handle as well.
First, with respect to the handle component and the flexible shaft. The handle has a pistol grip-styled design, having one or more, and preferably two, finger triggers which are independently coupled to at least one, and preferably two separate motors which each turn separate flexible drive shafts (described more fully, hereinbelow). The motors are each dual direction motors, and are coupled to a manual drive switch mounted to the top of the handle, by which the user can selectively alter the turning direction of each motor. In addition to the motor components, the handle further includes several other features, including: (1) an remote status indicator; (2) a shaft steering means; and (3) at least one additional electrical supply.
The flexible shaft comprises a tubular sheath, preferably formed of a simple elastomeric material which is tissue compatible and which is sterilizable (i.e., is sufficiently rugged to withstand an autoclave). Within the elastomeric sheath are a pair of smaller fixed tubes which each contain a flexible drive shaft which is capable of rotating within the tube. The flexible drive shaft, itself, simply must be capable of translating a torque from the motor in the handle to the distal end of the shaft, while still being flexible enough to be bent, angled, curved, etc. as the surgeon deems necessary to xe2x80x9csnakexe2x80x9d through the colon of the patient. As suggested above, in conjunction with the manually actuateable steering means mounted to the handle, the sheath further includes at least two sets of steering wires which are flexible, but are coupled to the inner surface of the sheath near the distal end thereof. The steering wires may be axially translated relative to one another by actuation of the steering means, which action causes the sheath to bend and curve accordingly.
Referring now to one possible surgical instrument attachment which was disclosed as a preferred embodiment in the above referenced co-pending application entitled xe2x80x9cAn Electromechanical Driver Device for use with Anastomosing, Stapling, and Resecting Instrumentsxe2x80x9d, the anastomosing and stapling attachment, this attachment comprises an anvil portion, and a staple, blade and reservoir portion, which includes a pair of turning drive shafts which are coupleable to the drive components of the shaft element described above, and a corresponding pair of advancing and retracting nuts mounted to the turning drive shafts, but which are prevented from rotating and therefore linearly advance and retract along the shafts when they turn.
The anvil portion is bullet shaped, having a blunt nosed top portion, a flat cutting support surface on the bottom, and a freely rotating coupling post extending axially from the bottom surface. This coupling post is designed to be selectively coupleable and removable from the corresponding nut mounted to one of the turning drive shafts.
The staple, blade, and reservoir portion (SBR portion) is cylindrical in shape, forming a housing which has a hollow interior. It is this hollow interior which forms the reservoir. On the axially outward facing surface of the cylindrical wall of the housing are a series of staple ports, through which the staples of the device are discharged. A series of staple drivers are mounted within the cylindrical walls, beneath the staple ports, for driving the staples therethrough. The blade is similarly cylindrical, and seats in the inside of the housing, against the inner surface of the wall thereof. Both the blade and the staple driver are mounted to the second nut, which is, in turn, mounted to the other turning drive shaft. As the tuning drive shaft rotates, the nut (which is constrained against rotating) advances along the shaft, thus linearly advancing the blade and staple driver. The blade and the staple driver are, therefore, selectively advanceable axially outward from the housing, in accordance with actuation of the appropriate trigger on the handle.
In a preferred embodiment set forth in the referenced application, the anvil portion and the SBR portion further comprise an electromagnetic sensor mechanism, coupled to the LCD indicator of the handle, which sensor is activated when the two portions have approached each other to the extent necessary for a safe staple firing, whereby the surgeon may have remote knowledge of the state of the attachment disposed within the colon.
An observed problem with prior art devices used in the anastomosing, stapling and resecting surgical procedure described above, relates to the best indications which the surgeon may remotely receive as to the conditions within the patients colon. For example, it is critical that the surgeon know whether the tissue being coupled forms a contiguous and sealed ring, such that the recoupled ends of the colon do not contain a hole through which bowel contents may leak into the body cavity. Post surgical infection rates due to such failures are a leading cause of complications and are often severe and are a leading cause of morbidity.
An associated issue of which surgeons who carry out these procedures must be cognizant relates to the ongoing viability of the tissue which has been resealed. A frequent post-surgical problem relates to the tissue necrosis which may occur if the staple ring is too tightly compressing the tissue, and preventing necessary blood flow thereto. A simple light-based mechanically measured distance indicator means is insufficient to avoid both of these problem. Prior art devices fail to provide the means by which information regarding the state of the tissue being manipulated may be measured and used by the surgeon, and the instrument itself, to ensure a more positive outcome.
It shall be understood that this problem, i.e., the failure of remotely controlled surgical instruments to provide for the gathering, displaying, and influencing of automatic actions, of information critical to the success of the surgical procedure simultaneously with the action of the device, is not limited to the specific instances discussed above. Rather, this failure is prevalent throughout surgical instrumentation.
It is therefore a principle object of the present invention to provide a surgical attachment which is remotely controlled and includes information-gathering sensors, communication and processing capacities, information storage capacity, and indicating means by which the user and/or remote decision-making systems may choose to control the instrument and activate the features of the attachment in accordance with the gathered and relayed information.
Other objects of the present invention shall be recognized in accordance with the description thereof provided hereinbelow, and in the Detailed Description of Preferred Embodiments in conjunction with the remaining Figures.
The preceding objects of the invention are provided by an electromechanical driver, a flexible shaft, and remote surgical attachment including a controller processor unit mounted in the handle which is connected via cabling in the flexible shaft to a sensor and memory unit in the remote attachment. More particularly, with respect to the bowel surgery anastomosing, resecting, and stapling attachment described above in the Description of the Prior Art, the present invention shall be set forth with respect to the same application. Specifically, with respect to the sensor and memory unit mounted in the anastomosing, resecting, and stapling attachment, the sensor utilized is a pulse oximeter.
First, as described above, the present invention is preferably embodied as a subsystem of a device which comprises three components, which are (1) an electromechanical driver, (2) a flexible shaft, and (3) an anastomosing, resecting, and stapling attachment.
First, with regard to the electromechanical driver, the handle has a pistol grip styled design, having at least two finger-actuatable triggers which independently initiate motors which turn drive shafts mounted within the flexible shaft. The handle further includes a remote status indicator coupled to the processor unit in the handle. This indicator provides either visual, audio, or electrical output (to be output to a separate display device). The handle and flexible shaft further include a shaft steering means comprised of steering wires controlled by a handle mounted motor drive system including a manually actuatable steering means for directing the steering means, for example, a joystick or trackball, described more fully in co-pending application U.S. Ser. No. 09/510,923, now issued as U.S. Pat. No. 6,517,565, entitled xe2x80x9cA Carriage Assembly for Controlling a Steering Wire Steering Mechanism within a Flexible Shaftxe2x80x9d, which has been assigned to the same assignee as the present invention, and which is incorporated herein fully by reference.
In this embodiment of the electromechanical driver, the driver components are integrated with the controller components. It should be noted that other embodiments of the electromechanical driver may comprise a driver unit which is physically separate from a controller unit. That is, the driver unit may comprise the above-described motors and the above-described steering means, and the controller unit may comprise the above-described triggers, the above-described remote status indicator, as well as the above-described manually actuatable steering means means. The controller unit components communicate with the driver unit components by wireless transmission, for example, through infrared, radio waves, other electromagnetic waves, or ultrasound. In such a configuration, for example, the driver unit may be located out of the surgeon""s arm""s reach, while the controller unit may be selectively coupleable to that portion of the flexible shaft which is closer to the patient and closer to the surgeon. It should be further understood that additional embodiments of the electromechanical driver assembly may comprise more than two separate units, and such units may each house only one, or more than one, of the above-described separate components, all communicating by wireless means as described above. For example, the remote status indicator described above could be part of a third unit which mounts to a visor wearable by the surgeon. It should be further understood that all communications between these components as described herein may in such alternative embodiments take place by wireless means.
Second, with respect to the flexible shaft, the shaft comprises a tubular sheath, preferably formed of a simple elastomeric material which is tissue compatible and which is sterilizable (i.e., is sufficiently rugged to withstand an autoclave). Within the elastomeric sheath are a pair of smaller fixed tubes, each of which contain a flexible drive shaft which is capable of rotating within the tube. As suggested above, in conjunction with the steering means mounted in the handle, the sheath further includes at least two steering wires which are flexible, but are coupled to the inner surface of the sheath near the distal end thereof. In addition, the flexible shaft includes a least one electrical lead and corresponding coupling terminals at each end, for coupling to the processor and controller means in the handle with the sensor and memory components in the distally mounted surgical attachment.
Third, with regard to the anastomosing, resecting, and stapling attachment, a single example of the many alternative surgical attachments which may include aspects of the present invention is now described. This attachment comprises a selectively advanceable and retractable anvil portion, and a staple, blade, sensor, and reservoir portion. This latter element includes the drive elements necessary to move the anvil forward and back, as well as the motive elements which drive the staples and blade through the tissue. These motive elements are coupleable to the drive components of the shaft element described above. Included in the staple, blade, sensor and reservoir portion, also, are a pulse oximeter sensor and a tissue proximity sensor, as well as a memory unit which contains important identification information which may be retrieved by the processor unit in the handle upon connection to the flexible shaft.
As stated above, when initially coupled to the flexible shaft (which shall be hereinafter taken to be permanently coupled to the handle unit), and the handle is powered up, the first internal act to take place is for the processor unit in the handle to query the memory unit in the attachment as to its identity and status. More particularly, as the anastomosing, resecting, and stapling attachments may come in different diameters, shapes, lengths, and stapling arrangement (as well as many other potential variations) which are readily readable by the handle mounted processor unit and displayed for the user either on a remote display panel to which the handle is coupled, or on a display screen which is integrally included in the handle itself.
The status of the attachment shall also be queried, for example, as to what the functionality of the attachment is, and whether or not it has been previously used, and therefore, no longer capable of firing a second time.
Once this information has been gathered, and it is determined that the attachment is the appropriate one, the surgical step for which this attachment is utilized may continue. In particular, the anvil tip is advanced via action of the drive motor and drive elements of the handle, shaft, and attachment, until it may be manually separated from the remainder of the attachment. The appropriate opening is made in the previously cut and stapled closed proximal end of the bowel and the anvil tip of the attachment is placed therein. The remainder of the attachment and the appropriate length of the flexible shaft is inserted through the rectum and up the bowel until the attachment coupling shaft is advanced through a small opening in the cut and stapled closed distal end of the bowel section.
After recoupling, the anvil portion is retracted toward the stapling portion until it is mechanically determined that the two portions are within the range which is appropriate for staple firing. At this time, the physician user is unable to simply remotely fire the staples. This lock out feature is maintained by the processor unit until such time as the surgeon causes the processor until in the handle to query the tissue proximity sensor and the pulse oximeter sensor in the attachment to determine if the tissues to be stapled together form a completely contiguous ring so that the two tubular sections of bowel can be properly mechanically united. This measurement may be made optically, or by any other suitable means, by which the transmission of some signal which should be blocked by the intervening tissue is received by an opposing sensor. The results of this query are then relayed back to the processor in the handle which carries out the appropriate analysis. If the proximity query results in a negative analysis outcome, an indicator light, audible alarm, or other suitable means of alerting the surgeon to this condition is provided. The processor will also disarm the stapling mechanism (by removing power to the drive mechanisms, for example) to prevent an attempted override by the surgeon.
If the proximity query results in a positive response, however, the next in the series of tests to determine if the surgeon may safely join the sections of bowel is carried out. Specifically, the processor in the handle activates the pulse oximeter sensor and queries it regarding whether the proper level of blood profusion remain in the tissue sections to be joined. As suggested above, if the stapling procedure has the effect of cutting off the necessary blood supply to sections of the joined tissue, a necrotic region will develop in the bowel, and future complications (which may be fatal) will arise. The results of this query are also relayed to the processor in the handle. Again, if the results of the processing of this information is negative, an indication of this state is provided by the processor. As above, if negative, the surgeon will be unable to mechanically fire the staples, as the processor will disarm the motor assembly.
Additional features and aspects of the present invention are set forth in greater detail in the description of the preferred embodiments provided hereinbelow.